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Evidence that Phenotypic g is Both Formative and Reflective From Four Large Genetically-Informative Samples

Published online by Cambridge University Press:  05 May 2025

Michael A. Woodley of Menie
Affiliation:
Independent Researcher, London, UK
Mateo Peñaherrera-Aguirre*
Affiliation:
University of Arizona, School of Animal and Comparative Biomedical Sciences, Tucson, Arizona, USA
John G.R. Fuerst
Affiliation:
Department of Biotechnology, University of Maryland Global Campus, Adelphi, Maryland, USA
*
Corresponding author: Mateo Peñaherrera-Aguirre; Email: [email protected]
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Abstract

Is general intelligence (g) a reflective construct, representing a latent causal entity underlying subtest performance, or a formative construct, better understood as an aggregate variable shaped by and summarizing variation across subtests? Genetically informative data provide a framework for testing whether a construct is reflective or formative by comparing common pathway and independent pathways structural equation models (SEMs). Previous studies using biometric SEMs have predominantly supported the reflective model, with phenotypic g mediating the effects of additive genetic and environmental influences on lower level abilities. In the current study, four large genetically informed datasets (three from the US and one from the UK) were analyzed to test three competing SEM models — common pathway, independent pathways, and merged — using Confirmatory Factor Analysis (CFA). Genetic g was estimated in each sample as a latent variable derived from polygenic scores indexing educational attainment and cognitive abilities. The models were compared as follows: the common pathway model, consistent with a reflective g, included a direct path from genetic g to phenotypic g; the independent pathways model, consistent with a formative g, featured indirect paths from genetic g to phenotypic g via subtests; and the merged model incorporated both direct and indirect paths. Across all four datasets, the merged model consistently provided the best fit (based on goodness-of-fit and parsimony criteria). Phenotypic g mediated between 31% and 81% of the effects of genetic g on subtests. These findings suggest that g functions as both a reflective and formative entity.

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Article
Copyright
© The Author(s), 2025. Published by Cambridge University Press on behalf of International Society for Twin Studies

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References

Ajnakina, O., & Steptoe, A. (2022). The English Longitudinal Study of Ageing (ELSA) Polygenic Scores 2022. https://doc.ukdataservice.ac.uk/doc/8773/mrdoc/pdf/8773_full_report_elsa_gwas_pgs_2022.pdf Google Scholar
Banks, J., David, B.G., Breedvelt, J., Coughlin, K., Crawford, R., Marmot, M., Nazroo, J., Oldfield, Z., Steel, N., Steptoe, A., Wood, M., & Zaninotto, P. (2024). English Longitudinal Study of Ageing: Waves 0–10, 1998–2023 [data collection, 40th ed.]. UK Data Service. SN: 5050.Google Scholar
Bates, T. (2025). Cognitive rationality is heritable and lies under general cognitive ability. Intelligence, 108, 101895. https://doi.org/10.1016/j.intell.2024.101895 CrossRefGoogle Scholar
Blankson, A. N., & McArdle, J. J. (2015). Measurement invariance of cognitive abilities across ethnicity, gender, and time among older Americans. Journals of Gerontology Series B: Psychological Sciences and Social Sciences, 70, 386397. https://doi.org/10.1093/geronb/gbt106 CrossRefGoogle ScholarPubMed
Bollen, K. A., & Pearl, J. (2013). Eight myths about causality and structural equation models. In: Morgan, S. (Ed.), Handbook of causal analysis for social research. Handbooks of sociology and social research. (pp. 301328). Springer.CrossRefGoogle Scholar
Borsboom, D., Mellenbergh, G.J., & van Heerden, J. (2003). The theoretical status of latent variables. Psychological Review, 110, 203219. https://doi.org/10.1037/0033-295X.110.2.203 CrossRefGoogle ScholarPubMed
Briley, D. A., & Tucker-Drob, E. M. (2013). Explaining the increasing heritability of cognitive ability across development: A meta-analysis of longitudinal twin and adoption studies. Psychological Science, 24, 17041713. https://doi.org/10.1177/0956797613478618 CrossRefGoogle ScholarPubMed
Bruins, S., Franic, S., Borsboom, D., Dolan, C., & Boomsma, D. (2023). Structural equation modeling in genetics. In Hoyle, R. H. (Ed.), Handbook of structural equation modelling (2nd ed., pp. 646663). Guilford Press.Google Scholar
Calvin, C. M., Deary, I. J., Fenton, C., Roberts, B. A., Der, G., Leckenby, N., & Batty, G. D. (2011). Intelligence in youth and all-cause-mortality: Systematic review with meta-analysis. International Journal of Epidemiology, 40, 626644. https://doi.org/10.1093/ije/dyq190 CrossRefGoogle ScholarPubMed
Coyle, T., Woodley Menie, M. A., Peñaherrera-Aguirre, M., Sarraf, M. A., & Madison, G. (2023). The heritability of ability tilts. Personality & Individual Differences, 213, 112187. https://doi.org/10.1016/j.paid.2023.112187 CrossRefGoogle Scholar
de la Fuente, J., Davies, G., Grotzinger, A. D., Tucker-Drob, E. M., & Deary, I. J. (2021). A general dimension of genetic sharing across diverse cognitive traits inferred from molecular data. Nature Human Behaviour, 5, 4958. https://doi.org/10.1038/s41562-020-00936-2 CrossRefGoogle ScholarPubMed
Davies, G., Lam, M., Harris, S. E., Trampush, J. W., Luciano, M., Hill, W. D., Hagenaars, S. P., Ritchie, S. J., Marioni, R. E., Fawns-Ritchie, C., Liewald, D. C. M., Okely, J. A., Ahola-Olli, A. V., Barnes, C. L. K., Bertram, L., Bis, J. C., Burdick, K. E., Christoforou, A., DeRosse, P., … Stott, D. J. (2018). Study of 300,486 individuals identifies 148 independent genetic loci influencing general cognitive function. Nature Communications, 9, 2098. https://doi.org/10.1038/s41467-018-04362-x CrossRefGoogle ScholarPubMed
Deary, I. J., Harris, S. E., & Hill, W. D. (2019). What genome-wide associations studies reveal about the association between intelligence and physical health, illness, and mortality. Current Opinion in Psychology, 27, 612. https://doi.org/10.1016/j.copsyc.2018.07.005 CrossRefGoogle ScholarPubMed
Franić, S. F. (2014). From structural equation models to next-generation sequencing: The evolving landscape of modern behavioral genetics [Unpublished PhD thesis]. Vrije Universiteit Amsterdam.Google Scholar
Franić, S., Dolan, C. V., Borsboom, D., Hudziak, J. J., van Beijsterveldt, C. E. M., & Boomsma, D. I. (2013). Can genetic help psychometrics? Improving dimensionality assessment bthrough genetic factor modelling. Psychological Methods, 18, 406433. https://doi.org/.1037/a0032755 CrossRefGoogle Scholar
Gross, A. L., Li, C., Briceño, E. M., Arce Rentería, M., Jones, R. N., Langa, K. M., Manly, J. J., Nichols, E., Weir, D., Wong, R., Berkman, L., Lee, J., & Kobayashi, L. C. (2023). Harmonisation of later-life cognitive function across national contexts: Results from the Harmonized Cognitive Assessment Protocols. The Lancet: Healthy Longevity, 4, e573e583. https://doi.org/10.1016/S2666-7568(23)00170-8 Google ScholarPubMed
Guardiola-Ripoll, M., & Fatjó-Vilas, M. (2023). A systematic review of the human accelerated regions in schizophrenia and related disorders: Where the evolutionary and neurodevelopmental hypotheses converge. International Journal of Molecular Sciences, 24, 3597. https://doi.org/10.3390/ijms24043597 CrossRefGoogle ScholarPubMed
Hudomiet, P., Hurd, M. D., & Rohwedder, S. (2022). Trends in inequalities in the prevalence of dementia in the U.S. Proceedings of the National Academy of Sciences USA, 119, e2212205119. https://doi.org/10.1073/pnas.2212205119 CrossRefGoogle Scholar
Huguet, G., Schramm, C., Douard, E., Tamer, P., Main, A., Monin, P., England, J., Jizi, K., Renne, T., Poirier, M., Nowak, S., Martin, C. O., Younis, N., Knoth, I. S., Jean-Louis, M., Saci, Z., Auger, M., Tihy, F., Mathonnet, G.,… _Jacquemont, S. (2021). Genome-wide analysis of gene dosage in 24,092 individuals estimates that 10,000 genes modulate cognitive ability. Molecular Psychiatry, 26, 26632676. https://doi.org/10.1038/s41380-020-00985-z CrossRefGoogle Scholar
Jonas, K. G., & Markon, K. E. (2016). A descriptivist approach to trait conceptualization and inference. Psychological Review, 123, 9096. https://doi.org/10.1037/a0039542 CrossRefGoogle ScholarPubMed
Jones, R. N., Manly, J. J., Langa, K. M., Ryan, L. H., Levine, D. A., McCammon, R., & Weir, D. (2024). Factor structure of the Harmonized Cognitive Assessment Protocol neuropsychological battery in the Health and Retirement Study. Journal of the International Neuropsychological Society, 30, 4755. https://doi.org/10.1017/S135561772300019 CrossRefGoogle ScholarPubMed
Kazali, E., Spanoudis, G., & Demetriou, A. (2024). g: Formative, reflective, or both. Intelligence, 107, 101870. https://doi.org/10.1016/j.intell.2024.101870 CrossRefGoogle Scholar
Lee, J. J., Wedow, R., Okbay, A., Kong, E., Maghzian, O., Zacher, M., Nguyen-Viet, T. A., Bowers, P., Sidorenko, J., Karlsson Linnér, R., Fontana, M. A., Kundu, T., Lee, C., Li, H., Li, R., Royer, R., Timshel, P. N., Walters, R. K…. Social Science Genetic Association Consortium. (2018). Gene discovery and polygenic prediction from a 1.1-million-person GWAS of educational attainment. Nature Genetics, 50, 11121121. https://doi.org/10.1038/s41588-018-0147-3 CrossRefGoogle Scholar
Lewis, G. J., & Bates, T. C. (2014). How genes influence personality: Evidence from multi-facet twin analyses of the HEXACO dimensions. Journal of Research in Personality, 51, 917. https://doi.org/10.1016/j.jrp.2014.04.004 CrossRefGoogle Scholar
Nelson, L. D., Barber, J. K., Temkin, N. R., Dams-O’Connor, K., Dikmen, S., Giacino, J. T., Kramer, M. D., Levin, H. S., McCrea, M. A., Whyte, J., Bodien, Y. G., Yue, J. K., Manley, G. T.; British Neurosurgical Trainee Research Collaborative (BNTRC). (2021). Validity of the brief test of adult cognition by telephone in level 1 trauma center patients six months post-traumatic brain injury: A TRACK-TBI study. Journal of Neurotrauma, 38, 10481059. https://doi.org/10.1089/neu.2020.729 CrossRefGoogle ScholarPubMed
Panizzon, M. S., Vuoksimaa, E., Spoon, K. M., Jacobson, K. C., Lyons, M. J., Franz, C. E., Xian, H., Vasilopoulos, T., & Kremen, W. S. (2014). Genetic and environmental influences on general cognitive ability: Is g a valid latent construct? Intelligence, 43, 6576. https://doi.org/10.1016/j.intell.2014.01.008.CrossRefGoogle Scholar
Peñaherrera-Aguirre, M., Sarraf, M. A., Woodley Menie, M. A., & Miller, G. F. (2023). The ten-million-year explosion: Paleocognitive reconstructions of domain-general cognitive ability (G) in extant primates. Intelligence, 101, 101795. https://doi.org/10.1016/j.intell.2023.101795 CrossRefGoogle Scholar
Plomin, R. (2018). Blueprint: How DNA makes us who we are. Allen Lane.Google Scholar
Procopio, F., Zhou, Q., Wang, Z., Gidziela, A., Rimfeld, K., Malanchini, M., & Plomin, R. (2022). The genetics of specific cognitive abilities. Intelligence, 95, 101689. https://doi.org/10.1016/j.intell.2022.101689 CrossRefGoogle ScholarPubMed
R Core Team. (2024). R: A language and environment for statistical computing. R Foundation for Statistical Computing.Google Scholar
Revelle, W. (2020). psych: Procedures for psychological, psychometric, and personality research. R package version, 2(9).Google Scholar
Rosseel, Y. (2012). lavaan: An R package for structural equation modeling. Journal of Statistical Software, 48, 136. https://doi.org/10.18637/jss.v048.i02 CrossRefGoogle Scholar
Savage, J. E., Jansen, P. R., Stringer, S., Watanabe, K., Bryois, J., De Leeuw, C. A., Nagel, M., Awasthi, S., Barr, P. B., Coleman, J. R. I., Grasby, K. L., Hammerschlag, A. R., Kaminski, J. A., Karlsson, R., Krapohl, E., Lam, M., Nygaard, M., Reynolds, C. A., Trampush, J. W., … Posthuma, D. (2018). Genome-wide association meta-analysis in 269,867 individuals identifies new genetic and functional links to intelligence. Nature Genetics, 50, 912919. https://doi.org/10.1038/s41588-018-0152-6 CrossRefGoogle ScholarPubMed
Shi, D., & Maydeu-Olivares, A. (2020). The effect of estimation methods on SEM fit indices. Educational and Psychological Measurement, 80, 421445. https://doi.org/10.1177/0013164419885164 CrossRefGoogle ScholarPubMed
Shikishima, C., Hiraishi, K., Yamagata, S., Sugimoto, Y., Takemura, R., Ozaki, K., Okada, M., Toda, T., & Ando, J. (2009). Is g an entity? A Japanese twin study using syllogisms and intelligence tests. Intelligence, 37, 256267. https://doi.org/10.1016/j.intell.2008.10.010 CrossRefGoogle Scholar
Ware, E. B., Hornish, U., Noltye, M, & Faul, J. D. (2024). HRS Polygenic ScoresRelease 5 2006–2012 genetic data sensitive health data. Survey Research Center, Institute for Social Research, University of Michigan.Google Scholar
Warne, R. T. (2020). In the know: Debunking 35 myths about human intelligence. Cambridge University Press.CrossRefGoogle Scholar
Williams, B. D., Chandola, T., & Pendleton, N. (2018). An application of Bayesian measurement invariance to modelling cognition over time in the English longitudinal study of ageing. International Journal of Methods in Psychiatric Research, 27, e1749. https://doi.org/10.1002/mpr.1749 CrossRefGoogle ScholarPubMed
Wood, M. S. (2015). Package ‘mgcv’. R Package Version, 1, 729 Google Scholar
Xia, Y., & Yang, Y. (2019). RMSEA, CFI, and TLI in structural equation modeling with ordered categorical data: The story they tell depends on the estimation methods. Behavior Research Methods, 51, 409428. https://doi.org/10.3758/s13428-018-1055-2 CrossRefGoogle ScholarPubMed
Zhang, Z. (2016). Multiple imputation with multivariate imputation by chained equation (MICE) package. Annals of Translational Medicine, 4, 30. https://doi.org/10.3978/j.issn.2305-5839.2015.12.63 Google ScholarPubMed